MOD TRANSPORT RATE IN MUD LAYER DUE TO WAVE ACTION

Tomoya Shibayama, Masakazu Okuno, Shinji Sato

Abstract

In order to calculate mud transport rate, two forms of transport should be considered, which are (1) mud mass transport in mud layer, and (2) suspended mud transport in water layer. The first type of transport (mass transport in mud layer) is greater than the second one in quantity under soft mud or fluid mud condition, therefore the first type of transport is mainly considered. The previously proposed methods to calculate the first type of transport are summarized and discussed. Then a new transport model called visco-elastic-plastic model is derived and some of the results of the model are shown. The model is based on the assumption that the fluid mud layer can be assumed to be viscoelastic fluid and when the magnitude of stress in mud layer exceeds the value of yield stress, the mud layer is modeled as visco-plastic fluid. Results of the new numerical model are compared with laboratory results and some discussions are given.